Method for the production of highly-active charcoal from wood



Patented. June 15, 1926.

UNITED STATES PATENT OFFICE.

PAUL 'WHLEB, OF MiNNHEIM-WISHLGELEGEN, GERMANY, ASSIG-NOR TO THE FIRM OF RHENANIA VEREIN CHEMISCHER" FABRIKEN ACTIEN-GESELLSCHAFT, ZWEIG- NIEDERLASSUN G MANNHEIM, MANNHEIM-WOHLGELEGEN, GERMANY, A. COR- PORATION OF GERMANY.

METHOD FOR THE PRODUCTION OF HIGHLY-ACTIVE CHARCOAI: FROM WOOD.

No Drawing. Application filed September 1, 1921,

The present invention relates to the production of charcoal from wood and has for its object the transformation of wood into highly active charcoal in granulous form.

5 Attempts to attain this object by impreg nating the wood with alkali and by subsequent carbonization have failed, as the material crumbled topowder when glowed. According to the present invention the prob- 1 lem is solved in a very satisfactory manner by heating wood cut into small hits at a moderate temperature, for instance, ADO-500 (1, under exclusion of air, until complete carbonization hasbeen effected; by-

then impregnating the material with alkali and completing the carbonization process by heating to brightest red heat, for instance, at a temperature of 10001100 0., under exclusion of air.

tinued until the wood is completely carbonized. Both beatings are carried out under exclusion of air.

For the impregnation, saturated or'highly concentrated solutions are preferably used with which the vproduct from the first heating is saturated.

It has further been discovered that a highl active coal in granulous form is obtaine when thewood cut into small bits is first-carbonized under exclusion of air at a moderate temperature, for instance at dark red heat, whereupon the product from car- "bonization is saturated with alkali, e. g., potash, and in finishing the carbonizing process by heating under exclusion of-air the subred heat.

40 Examples.

1. The wood cut into small bits of for instance 3-5 millimeters is heated to 400500 0., under exclusion of air, so that it preserves generally its shape. The coal obtained is saturated with a solution of potash or of potassium hydroxide, alkali being eventually added. The mass obtained is i then heated under exclusion of air to bri htest red heat, e. g. up to 1000 or 1100 or 59 even more. The carbon which is thus pro- I duced, and which on the whole has preserved the shape of the initial material, is washed The first heating (too-500 c.) ea..

Serial No. 497,666, and in Germany April 14, 1917.

of alkali, suitable electrolytes, that is to say' salts of an alkali or an acid are used which does not cause the swelling of the mass when the wood is being heated, the wood which has been thus preliminarily treated being carbonized at moderate temperature, whereupon, after lixiviation of the electrolyte and incorporation of alkalis, the final carbonization is carried through at high temperature in presence of the alkalis.

2. Wood cut into small bits is saturated with a concentrated solution of chloride of calcium and heated under exclusion of air up to about 400 G. The product from carbonization is freed from the chloride of calcium by lixiviation, dried eventually, and

that of the best animal charcoalsand blood charcoals, obtainable in commerce.

I claim 1. The improved method for the production of active carbon in' granular form which consists in carbonizing under exclusion of air at a temperature of 300 to 500 '0. wood cut in.o bits of small size, in incorporating alkali in the product and in heating the roduct under exclusion of air at bright re heat.

2. The improved method for the produc-- tion of active carbon in granular form which consists in carbonizing under exclusion of air at a temperature of 300 to. 500 0. wood cut into small bits impregnated with an electrol to which does not make the wood swell,

in eeing the product of the electrolyte, in

incorporating alkali in the productand in at bright red heat.

3. The improved method for the production of active carbon in granular form which consists in carbonizing under exclusion of air at a temperature of 300 to 500 C. wood cut into bits of a size of 2 to 5 mm. impregnated with a solution of chloride of calcium, in freeing the product of the electrolyte, in incorporating alkali in the product and in heating the product under exclusion of air at bright red heat.

' 4. The improved method for the production of active carbon in granular form which consists in carbonizing under exclusion of air at a temperature of 300 to 500 C. small bits of wood, in saturating the product with a concentrated solution of alkaline com-' pounds and in heating the product under exclusion of air at bright red heat.

5. The improved method for the production of active carbon in granular form which consists in carbonizing under exclusion of air at a temperature of 300 to 500 C. small bits of wood impregnated with an electrolyte which does not make the wood swell, in freeing the product of the electrolyte, in saturating the product with a concentrated solution of alkaline compounds and in heatin the product under exclusion of air at bright red heat.

6. The improved method for the production of active carbon in granular form which consists in carbonizing under exclusion of air at a temperature of 300 to 500 C. wood cut into small bits and impregnated with a solution of chloride of calcium, in lixiviating the product with a concentrated solution of alkaline compounds and in heating the product under exclusion of air at bright red heat.

7. The improved method for the production of active carbon in granular form which consists in carbonizing under exclusion of air at a tem erature of 300 to 500 C. small bits of woo in saturating the product with a solution of caustic potash and in heating the product under exclusion of air at bright red heat. I

8. The improved method for the production of active carbon in granular form which consists in carbonizing under exclusion of a r at a temperature of 300 to 500 C. small bits of wood impregnated with an electro lyte which does not make the wood swell, in freeing the product of the electrolyte, in impregnating the product with concentrated.

caustic potash solution and in'heating the 1mass under exclusion of air at bright red eat.

9. The improved method for the production of active carbon in granular form which consists in carbonizing under exclusion of air at a temperature of 300 to 500 C. small bits of wood which have been impregnated with a solution of chloride of calcium, in freeing the product of the chloride of calcium by lixiviation, in impregnating the product with concentrated caustic potash solution and in heating the mass under ex-. clusion of air at bright red heat.

10. The improved method for the production of active carbon in granular form which consists in carbonizing under exclusion of air at a temperature of 300 to 500 C. small bits of wood,'in saturating the product with a concentrated solution of potassium hydroxide, and in heating the product under exclusion of air at bright red heat.

11. The improved method for the production of active carbon in granular form which consists in carbonizing under exclusion of air at atemperature of 300 to 500 C. small bits' of wood, in impregnating the product with an electrolyte which does not make the wood swell, in freeing the product of the electrolyte, in impregnating the product with a concentrated solution of potassium hydroxide and in heating the mass under exclusion of air at bright red heat.

12. The improved method for the production of active carbon in granular form which consists in carbonizing under exclusion of air at a temperature of 300 to 500 C. small bits of wood impregnated with a solution of chloride of calcium, in freeing the product of the chloride of calcium, in impreg nating the same with a concentrated solution of potassium hydroxide and in heating the same at bright red heat.

13. The improved method for the production of active carbon in granular form which consists in carbonizing under exclusion of air at a temperature of 300 to 500 C. small bits of wood, in incorporating alkali in the product, inheatin the product under exclusion ofair at brlght red heat, in lixiviatr ing the product from the second heating and in drying the same.

In testimony whereof I have signed my name to this specification.

DR. PAUL WOHLER. 

